Cleaning applications typically involve the removal of foreign matter off surfaces. In laundry applications, this involves the removal of both hydrophobic and hydrophilic soils (food stains, blood, grass, dirt, grease, oils, etc.) off various fabrics including cotton, polyester, silk, rayon, wool and various blends of these materials. For the cleaning of fabric articles, the consumer has two choices for removal of soils: conventional water based cleaning and dry cleaning (i.e., non-aqueous based cleaning).
Conventional laundry cleaning is carried out with relatively large amounts of water, typically in a washing machine at the consumer's home, or in a dedicated place such as a coin laundry. Although washing machines and laundry detergents have become quite sophisticated, the conventional laundry process still exposes the fabric articles to a risk of dye transfer, shrinkage and wrinkling. Significant portions of fabric articles used by consumers are not suitable for cleaning in a conventional laundry process. Even fabric articles that are considered “washing machine safe” frequently come out of the laundry process badly wrinkled and require ironing.
The dry cleaning process refers to a process where low or no water is used in the cleaning system; it uses various non-aqueous organic solvents, such as halocarbons, hydrocarbons, densified carbon dioxide, glycol ethers and silicones. By avoiding the use of large amount of water, the dry cleaning process minimizes the risk of damages to the fabric articles. Generally, water-sensitive fabrics such as silk, wool, rayon, and the like, are cleaned in this manner.
However, some soils that were easily removed from fabrics in a conventional aqueous based cleaning process are not as effectively removed by conventional dry cleaning solvents. Typically, the dry-cleaner removes such soils by hand prior to the dry-cleaning process. These methods are complex, requiring a wide range of compositions to address the variety of stains encountered, very labor intensive and often result in some localized damage to the treated article.
Additionally, conventional detergent compositions are developed for water based cleaning; as such, the components (such as soil release polymers, bleaches, enzymes, other fabric care actives) therein are designed for water based cleaning processes. It has been found that these conventional cleaning agents and fabric care actives do not function efficiently in dry cleaning solvents, possibly due to low compatibility with these solvents. For example, removal of typical water-based and alcohol-based soils is very limited using the dry cleaning processes. A common problem is spotty deposition of the cleaning agents and/or fabric care actives that delivers spotty, thus unsatisfactory results. Another common problem is that the dry cleaning solvents delivers poorer wetting of the fabrics, compared to water; consequently, the cleaning agents and/or fabric care actives exhibit relatively poorer penetration into the fabrics when used in the dry cleaning process and deliver less than satisfactory results.
To maximize fabric cleaning or fabric care benefits in such a system, it is desirable to get the cleaning agents and/or fabric care actives evenly deposited on the fabric article being treated. It is also desirable to be able to efficient deposit and deliver the cleaning agents and fabric care actives to the fabric articles being treated; thus, satisfactory cleaning and/or fabric care benefits can be achieved economically by using minimal amounts of solvents and detergent components are used.
It is also desirable to have a delivery system wherein the cleaning agents and/or fabric care actives are substantially evenly dispersed such that these components are even deposited on the fabric article in a dry cleaning process.
It is further desirable that the composition contains a substantially evenly dispersed water droplets in the dry cleaning solvent matrix and the cleaning agents and/or fabric care actives are preferentially disposed in the water droplets.